Endoscope system

ABSTRACT

An endoscope system includes an endoscope, a display device, and a cable interconnecting the endoscope and the display device. The endoscope includes an elongated body extending distally from a handle. An image sensor is disposed within a distal portion of the elongated body, a lens is disposed at a distal end of the elongated body, and a light source including one or more light emitting elements is integrated into the distal end of the elongated body and positioned radially outward of the lens. An integrated processor is disposed within the handle.

TECHNICAL FIELD

The present disclosure relates to endosurgical devices and systems forobserving internal features of a body during minimally invasive surgicalprocedures, and more particularly, to endoscope systems and the like.

BACKGROUND

Endoscopes are introduced through an incision or a natural body orificeto observe internal features of a body. Conventional endoscopes includea light transmission pathway, including a fiber guide, for transmittinglight from an external light source through the endoscope to illuminatethe internal features of the body. Conventional endoscopes also includean image retrieval pathway for transmitting images of these internalfeatures back to an eyepiece or external video system for processing anddisplay on an external monitor.

SUMMARY

The present disclosure is directed to endoscopes and endoscope systemshaving a light source and camera integrated into a distal end portion ofthe endoscopes and an integrated processor disposed within a handle ofthe endoscopes for controlling the endoscope systems.

According to an aspect of the present disclosure, an endoscope includesa handle and an elongated body extending distally from the handle. Theelongated body includes a distal portion terminating at a distal end. Animage sensor is disposed within the distal portion of the elongatedbody; a lens is disposed at the distal end of the elongated body, and alight source including one or more light emitting elements is integratedinto the distal end of the elongated body and positioned radiallyoutward of the lens. In embodiments, the light emitting elements aredisposed in a crescent shape around a portion of the lens. The lightemitting elements may be LEDs. The image sensor may be a backsideilluminated sensor. In embodiments, the image sensor is a highdefinition CMOS sensor. The lens may be a focus free lens.

The endoscope may include a passive thermal control system. Inembodiments, a thermally conductive substrate is affixed to the lightsource. A heat sink may be placed in contact with the thermallyconductive substrate. In some embodiments, a thermally conductiveadhesive is disposed between the heat sink and the thermally conductivesubstrate. In certain embodiments, the heat sink is cylindrical in shapeand positioned in full contact with a cylindrical wall of the elongatedbody.

In embodiments, the endoscope includes a processor disposed within thehandle. The processor includes a system controller, an imagingsubsystem, a video processing subsystem, and peripheral controllers fortransmitting data to and from external devices, such as the image sensorand the light source. In embodiments, the processor is a system-on-chip.

According to another aspect of the present disclosure, an endoscopeincludes a handle including a handle housing including a grip portionand a control portion. The handle housing defines an inner chambercontaining a plurality of circuit boards for powering and controllingthe endoscope system. In embodiments, the handle housing includes: amain board including a processor and memory for system control, datacapture, image processing, and video output; a power board including anintegrated power chip to manage system power; a button board toenable/disable user controls; and a switch board to power the system onand off.

The button board may be positioned in the control portion of the handleand the main board may be positioned in the grip portion of the handle.In embodiments, the power board is disposed in the grip portion of thehandle, and in certain embodiments, the switch board is positioned inthe grip portion of the handle.

The endoscope may further include an elongated body extending distallyfrom the handle. The elongated body includes a camera including an imagesensor disposed in a distal portion of the elongated body and a lensdisposed at the distal end of the elongated body. The elongated bodyalso includes a light source disposed at a distal end of the elongatedbody. The processor includes a peripheral controller for controlling thetransmission of data between the processor and the camera and aperipheral controller for controlling the transmission of data betweenthe processor and the light source.

Further details and aspects of exemplary embodiments of the presentdisclosure are described in more detail below with reference to theappended figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure are described herein withreference to the accompanying drawings, wherein:

FIG. 1 is a front, perspective view of an endoscope system of the priorart;

FIG. 2 is front, perspective view illustrating a schematic configurationof the endoscope system of FIG. 1;

FIG. 3 is a side view illustrating a schematic configuration of anoptical system of the endoscope system of FIG. 1;

FIG. 4 is a front, perspective view illustrating a schematicconfiguration of another endoscope system of the prior art;

FIG. 5 is a perspective, partial cutaway view illustrating a schematicconfiguration of a distal end of an endoscope of the endoscope system ofFIG. 4;

FIG. 6 is a perspective view of an endoscope in accordance with anembodiment of the present disclosure;

FIG. 7 is a front, perspective view illustrating a schematicconfiguration of an endoscope system in accordance with an embodiment ofthe present disclosure;

FIG. 8 is a schematic illustration of a camera of the endoscope of FIG.6;

FIG. 9 is an end view illustrating a schematic configuration of a distalend of an endoscope in accordance with an embodiment of the presentdisclosure;

FIG. 10 is a side, cross-sectional view of a distal portion of theendoscope of FIG. 6;

FIG. 11 is a side, perspective view, with parts separated, of the distalportion of the endoscope of FIG. 10;

FIG. 12 is a block diagram of system components of the endoscope systemof FIG. 7;

FIG. 13 is a block diagram of an integrated processor of FIG. 12; and

FIG. 14 is a top, perspective view of a handle of the endoscope of FIG.6.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed endoscope and endoscope system isdescribed in detail with reference to the drawings, in which likereference numerals designate identical or corresponding elements in eachof the several views. As used herein, the term “distal” refers to thatportion of a structure that is farther from a user, while the term“proximal” refers to that portion of a structure that is closer to theuser. As used herein, the term “subject” refers to a human patient orother animal. The term “clinician” refers to a doctor, nurse, or othercare provider and may include support personnel. The term “about” shallbe understood as a word of approximation that takes into accountrelatively little to no variation in a modified term (e.g., differing byless than 2%).

Referring initially to FIGS. 1-3, a prior art endoscope system 1includes an endoscope 10, a light source 20, a video system 30, and adisplay device 40. The light source 20, such as an LED/Xenon lightsource, is connected to the endoscope 10 via a fiber guide 22 that isoperatively coupled to the light source 20 and to an endocoupler 16disposed on, or adjacent to, a handle 18 of the endoscope 10. The fiberguide 22 includes, for example, fiber optic cable which extends throughthe elongated body 12 of the endoscope 10 and terminates at a distal end14 of the endoscope 10. Accordingly, light is transmitted from the lightsource 20, through the fiber guide 22, and emitted out the distal end 14of the endoscope 10 toward a targeted internal feature, such as tissueor an organ, of a body of a patient. As the light transmission pathwayin such a configuration is long, for example, the fiber guide 22 may beabout 1 m to about 1.5 m in length, only about 15% (or less) of thelight flux emitted from the light source 20 is outputted from the distalend 14 of the endoscope 10.

The video system 30 is operatively connected to an image sensor 32mounted to, or disposed within, the handle 18 of the endoscope 10 via adata cable 34. An objective lens 36 is disposed at the distal end 14 ofthe elongated body 12 of the endoscope 10 and a series of spaced-apart,relay lenses 38, such as rod lenses, are positioned along the length ofthe elongated body 12 between the objective lens 36 and the image sensor32. Images captured by the objective lens 36 are forwarded through theelongated body 12 of the endoscope 10 via the relay lenses 38 to theimage sensor 32, which are then communicated to the video system 30 forprocessing and output to the display device 40 via cable 39.

As the image sensor 32 is located within, or mounted to, the handle 18of the endoscope 10, which can be up to about 30 cm away from the distalend 14 of the endoscope 10, there is loss of image information in theimage retrieval pathway as it is difficult to get a high quality imageat every point along the whole working distance of the relay lenses 38.Moreover, due to light loss on the relay lenses 38, the objective lens36 cannot include a small aperture. Therefore, the depth of field islimited and a focusing module (not shown) is typically utilized in theendocoupler 16 to set the objective lens 36 to a desired focal point,which a clinician must adjust when moving the endoscope 10 during asurgical procedure. Also, rotation of the fiber guide 22 will alsorotate the relay lenses 38, which changes the viewing angle during use,and the fiber guide 22 also tends to fall due to the force of gravity.Accordingly, a clinician needs to adjust and/or hold the fiber guide 22during use to keep the view stable, which is inconvenient duringoperation.

As shown in FIGS. 4 and 5, another prior art endoscope system 1′, whichis substantially similar to endoscope system 1 and therefore will onlybe described with respect to the differences therebetween, includes theimage sensor 32 in a distal portion 13 of the elongated body 12 of theendoscope 10′ such that the image retrieval pathway between theobjective lens 36 and the image sensor 32 is shorter than that of theendoscope system 1. The endoscope system 1′ adopts the same lighttransmission pathway as that of the endoscope system 1 (i.e., from thelight source 20 and through the fiber guide 22), and thus lightconsumption on transmission is still large. However, the fiber guide 22may be integrated with the data cable 34, thereby making the endoscope10′ easier to operate as a clinician does not need to adjust the fiberguide 22 during use.

Referring now to FIGS. 6 and 7, an endoscope system 100 of the presentdisclosure includes an endoscope 110, a display 120, and a cable 130connecting the endoscope 110 and the display 120. A camera 140, a lightsource 150, and an integrated processor 160 are contained within theendoscope 110.

The endoscope 110 includes a handle 112 and an elongated body 114 havinga cylindrical wall 114 a extending distally from the handle 112 along alongitudinal axis “x.” The elongated body 114 includes a distal portion116 terminating at a distal end or tip 118. The handle 112 includes ahandling housing 112 a including a grip portion 113 for handling by aclinician and a control portion 115 including actuating elements 115 a(e.g., buttons, switches etc.) for functional control of the endoscope110.

As shown in FIG. 8, in conjunction with FIG. 7, the camera 140 isdisposed within the elongated body 114 of the endoscope 110. The camera140 includes an image sensor 142 disposed within the distal portion 116of the elongated body 112 proximal of a lens 144 that is positioned atthe distal end 118. The image sensor 142 may be a charge-coupled device(CCD), a complementary metal-oxide-semiconductor (CMOS), or a hybridthereof. In embodiments, the image sensor 142 is a highly sensitive,backside illuminated sensor (BSI). In embodiments, the lighting fluxrequired by the image sensor 142 may be up to about 20 lm.

As the image retrieval pathway is shortened over that of traditionalendoscope systems (e.g., FIG. 1) and the need for relay lenses iseliminated, the depth of field can be expanded and optimized.Accordingly, the lens 144 may include a depth of field from about 20 mmto about 110 mm with optimized image quality and a field-of-view ofabout 100 degrees. In embodiments, the lens 144 is a focus free lens. Ascompared to traditional endoscopes, a focus free lens relies on depth offield to produce sharp images and thus, eliminates the need to determinethe correct focusing distance and setting the lens to that focal point.Accordingly, the aperture of the lens 144 can be relatively small,taking up less space at the distal end 118 of the elongated body 114. Inembodiments, the outer diameter of the lens 144 is up to about 6 mm.

The light source 150 is disposed at the distal end 118 of the endoscope110. Light source 150 includes one or more high efficiency lightemitting elements 152, such as light-emitting diodes (LED). Inembodiments, the light emitting elements 152 have a luminous efficacy ofup to about 80 lm/W (lumen/watt). As compared to traditional endoscopes,the light source of the present disclosure eliminates the need for theuse of an external light source and fiber guide, which can lower thecost of the endoscope system, simplify the endoscope system structure,and reduce light consumption and/or light distortion during lighttransmission.

The light emitting elements 152 are arranged radially outward of thelens 144 at the distal end 118 of the elongated body 114 of theendoscope 110. The light source 150 may include a plurality ofindividual light emitting elements 152 arranged in an annular ring, suchas an LED ring, around the lens 144 (FIG. 7) to ensure adequate and evenlight distribution. In some embodiments, such as that shown in FIG. 9, adistal end 118′ of an endoscope 100′ may include a plurality ofindividual light emitting elements 152′ arranged in a crescent or arcshape around a portion of the lens 144′. The dimensional area of thelight source 150 at the distal end 118 of the endoscope may be about, orsmaller than, 0.4 cm², with the total light output area being no largerthan about 0.1 cm². To reduce the heat output from such a small area bythe high density of light, thermal control is managed by reducing heatgeneration and/or increasing heat conduction.

Heat generation may be managed, for example, by controlling the luminousefficacy of the light emitting elements 152 and the lighting fluxrequired by the image sensor 142. In embodiments, the endoscope 100 ofthe present disclosure includes high efficiency LED light emittingelements 152 and a BSI CMOS sensor 142. The BSI CMOS sensor 142 reducesthe lighting flux required to get a bright and clear image in a desiredbody cavity over image sensors utilized in traditional endoscopes.Accordingly, in embodiments where, for example, about 20 lm of lightingflux is required, such as within an abdomen of a patient, the powerconsumption of LED light emitting elements 152 having a luminousefficacy of about 80 lm/W will be about 0.25 W (20 lm/80 lm/W=0.25 W).As about 80% of the power consumption of an LED is typically turned intoheat, an LED light emitting element 152 with 0.25 W power consumptionwould generate no more than about 0.2 W of heat, which is a relativelyvery small amount of heat that can be controlled by a passive thermalsystem.

To increase heat conduction, a passive thermal control system includes aplurality of thermally conductive materials in successive contact witheach other so that heat flows from an area of higher temperature to oneof lower temperature thereby transporting the excess heat away from thesource into the ambient environment. As shown in FIGS. 10 and 11,contained within the cylindrical wall 114 a of the endoscope 110 is afixture 170 for fixing the lens 144 and a heat sink 172 within thedistal portion 116 of the elongated body 114, a thermally conductivesubstrate 174 in contact with a distal side 172 a of the heat sink 172,and a light source 150 affixed to a distal side 174 a of the thermallyconductive substrate 174. Heat generated by the light source 150 isconducted to the thermally conductive substrate 174, the heat sink 172,the cylindrical wall 114 a of the elongated body 114, and dissipatedinto the surrounding air as shown by arrows “A”.

In embodiments, a thin coating of a thermally conductive adhesive 173may be applied to the distal side 172 a of the heat sink 172 to increasethe heat conduction between the heat sink 172 and the substrate 174. Theheat sink 172 may be shaped as a cylinder that is dimensioned to fitwithin and fully contact the inner surface of the cylindrical wall 114 aof the elongated body 114, thereby maximizing the contact area betweenthe heat sink 172 and the cylindrical wall 114 a. The profile of theheat sink 172 may be designed to match the lens 144 and the light source150 so that in addition to conducting heat, the heat sink 172 also aidsin fixing the lens 144 and the light source 150 within the elongatedbody 114.

Referring now to FIGS. 12 and 13, the integrated processor 160 isdesigned for master control of the endoscope system 100. The processor160 is an integrated circuit including a system controller 162, varioussubsystems 164, such as an imaging subsystem 164 a and a high definitionvideo processing subsystem 164 b, and peripherals 166, such asinput/output (I/O) interfaces for controlling data transmission toand/or from external devices, such as the image sensor 142, the lightsource 150, the actuating elements 115 a in the control portion 115 ofthe handle 112, and the display device 120. The processor 160 is alsoresponsible for the configuration and control of memory 168. Inembodiments, the processor 160 is a system-on-chip (SoC). Compared totraditional hardware architecture, the power consumption of a SoC is lowresulting in less heat generation. Accordingly, thermal control of theendoscope is benefited from a high level integrated, low powerconsumption SoC.

The processor 160 is configured and designed to capture Full HD raw datafrom the camera 140 and to transmit the data to the imaging subsystem164 a for video processing, including, for example, color conversion,defect correction, image enhancement, H3A (Auto White Balance, AutoExposure, and Auto Focus), and resizer. The data is then transmitted tothe high definition video processing subsystem 164 b for wrapping of theprocessed data, and finally to an HDMI output 169 for image display onthe display device 120. The hardware modules may be tailored to controlpower consumption. In embodiments, some hardware functional blocks, suchas a high definition video image co-processor 161, and some peripherals166, such as Ethernet and some I/O interfaces, may be disabled. Suchsystem software optimization of the video pipeline results in lowerresource requirements and the tailored hardware modules optimize powerconsumption for thermal control.

As shown in FIG. 14, in conjunction with FIGS. 12 and 13, the hardwarestructure may include multiple circuit boards to maximize the use of thethree dimensional space within the handle housing 112 a and/or minimizethe dimensional size of the handle 112 to a smaller and lightweightconstruction. The handle 112 defines an inner chamber containing: a mainboard 180 including the processor 160 and the memory 168 for performingsystem control, data capture, imaging processing, and video output; apower board 182 including an integrated power chip 182 a to manage thesystem's power; a button board 184 operably associated with theactuating elements 115 a of the control portion 115 of the handle 112for enabling/disabling a user interface on screen display menu, systemfunctional controls and shortcuts; and a switch board 186 for poweringthe whole system on and off. The cable 130 connecting the endoscope 110and the display 120 may, in addition to the HDMI data pathway, include apower wire and converter for converting alternating current (e.g.,110/220V AC) into direct current (e.g., 5V DC) for system power.

EXAMPLES Example 1

An endoscope was constructed which included three high efficiency LEDshaving a luminous efficacy of about 80 lm/W and an OV2724 CMOS HD imagesensor which is commercially available from OmniVision of Santa Clara,Calif. A passive thermal control system was designed to include thethermally conductive materials provided in Table 1 below.

TABLE 1 Thermal Conductive Materials in a Thermal Control SystemMaterial Thermal Conductivity (W/m * K) Ceramic substrate 320 Siliconethermal adhesive 2-5 Aluminum heat sink 230 Stainless steel cylindricalwall 16 Air 0.024

Example 2

The thermal control of the endoscope of Example 1 was tested bymeasuring the temperature at the surface of the distal end of theelongated body of the endoscope inside an artificial abdominal cavityhaving a 298.8K environment temperature after the endoscope waspowered-on for 60 minutes. As shown in Table 2 below, the temperaturerise was under 10K for a 20 lm flux, which means that the temperature atthe distal end of the endoscope was not over about 42° C. during use.

TABLE 2 Temperature Test Results Temperature Temperature Flux (lm)Voltage (V) Current (mA) (K) rise (K) 7.29 7.789 10 296.23 2.48 11.177.839 15 297.26 3.56 14.54 7.871 20 298.52 5.31 18.74 7.904 25 299.886.13 22.43 7.929 30 300.78 7.03 26.14 7.951 35 303.88 10.13

Example 3

The lighting stability of the endoscope of Example 1 was tested bycontinually working the endoscope for over a 72 hour period under thesame test conditions of the temperature test of Example 2. As shown inTable 3 below, the temperature was successfully controlled by thepassive thermal control system.

TABLE 3 Stability Test Results Flux (lm) Voltage (V) Current (mA) Time(h, min) 20.74 7.937 30  0 h 00 min 21.16 7.936 30  4 h 26 min 21.017.934 30  5 h 14 min 20.29 7.933 30 22 h 56 min 20.80 7.933 30 29 h 08min 20.64 7.929 30 50 h 21 min 20.33 7.925 30 74 h 01 min

It will be understood that various modifications may be made to theembodiments described herein. Therefore, the above description shouldnot be construed as limiting, but merely as exemplifications of variousembodiments. Those skilled in the art will envision other modificationswithin the scope and spirit of the claims appended thereto.

What is claimed is:
 1. An endoscope comprising: a handle; an elongatedbody having a cylindrical wall extending distally from the handle, thecylindrical wall of the elongated body including a distal portionterminating at a distal end; an image sensor disposed within the distalportion of the cylindrical wall; a lens disposed at the distal end ofthe cylindrical wall; a light source including light-emitting diodesdisposed at the distal end of the cylindrical wall and positionedradially outward of the lens; a thermally conductive substrate disposedwithin the distal portion of the cylindrical wall and including a distalside affixed to the light source; a heat sink disposed within the distalportion of the cylindrical wall and extending to the distal end, theheat sink having a cylindrical shape including an outer surface in fullcontact with the cylindrical wall of the elongated body and an innersurface having a profile matching the lens and the light source, theheat sink including a distal side coupled to the thermally conductivesubstrate; and a thermally conductive adhesive disposed between thedistal side of the heat sink and the thermally conductive substrate. 2.The endoscope of claim 1, wherein the light-emitting diodes are disposedin a crescent shape around a portion of the lens.
 3. The endoscope ofclaim 1, wherein the image sensor is a backside illuminated sensor. 4.The endoscope of claim 1, wherein the image sensor is a BSI CMOS sensor.5. The endoscope of claim 1, wherein the lens is a focus free lens. 6.The endoscope of claim 1, further comprising an integrated processordisposed within the handle.
 7. The endoscope of claim 6, wherein theprocessor includes a system controller, an imaging subsystem, a videoprocessing subsystem, and peripheral controllers for transmitting datato and from the image sensor and the light source.
 8. The endoscope ofclaim 6, wherein the processor is a system-on-chip.
 9. The endoscope ofclaim 6, wherein the handle includes a grip portion and a controlportion having actuating elements for functional control of theendoscope, and the cylindrical wall of the elongated body is coupled tothe control portion of the handle.
 10. The endoscope of claim 9, furthercomprising a main board including the processor and memory, the mainboard positioned in the grip portion of the handle.
 11. The endoscope ofclaim 10, further comprising a button board to enable and disable usercontrols, the button board positioned in the control portion of thehandle and operably associated with the actuating elements.
 12. Theendoscope of claim 11, further comprising a power board having anintegrated power chip to manage system power, the power board positionedin the grip portion of the handle.
 13. The endoscope of claim 12,further comprising a switch board to power the endoscope on and off, theswitch board positioned in the grip portion of the handle.
 14. Theendoscope of claim 9, wherein the grip portion and the control portionof the handle extend linearly along a longitudinal axis defined by theelongated body.
 15. The endoscope of claim 1, wherein the thermallyconductive substrate is a ceramic substrate.
 16. The endoscope of claim1, wherein the heat sink is formed from aluminum.
 17. The endoscope ofclaim 1, wherein the cylindrical wall is formed from stainless steel.18. The endoscope of claim 1, wherein the light-emitting diodes have aluminous efficacy of about 80 lm/w.
 19. The endoscope of claim 1,wherein the lens extends proximally through the heat sink, and thethermally conductive substrate and the light source are disposed withinthe heat sink.
 20. The endoscope of claim 1, wherein a fixture isdisposed within the cylindrical wall proximal to the lens and the heatsink, a distal surface of the fixture positioned adjacent to the lensand in axially spaced relation from the heat sink.